Electron discharge device



Sept- 20, 1938- A. L.'SAMUEL 2,130,510

ELECTRON DISCHARGE DEVICE Filed June 30, 1937 FIG. I

% III/I4 /NVENTOR A. L SAMUEL BY OmMMue/l ATTORNEY Patented Sept. 20,1938 UNITED STATES PATENT OFFICE Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation of New York Application June 30,

13 Claims.

This invention relates to electron discharge devices and moreparticularly to such devices, for example of the magnetron type,suitable for the generation and amplification of ultra-high frequencyimpulses.

One object of this invention is to increase the power capacity of highfrequency electron discharge devices.

Another object of this invention is to facilitate 0 the production of astrong concentrated magnetic field adjacent the cathode in devices ofthe magnetron type.

A further object of this invention is to reduce end cooling effects inthermionic cathodes in electron discharge devices.

In one illustrative embodiment of this invention, a magnetron comprisesa linear incandescible filamentary cathode and a cylindrical anodeencompassing the cathode and mounted coaxially therewith.

In accordance with one feature of this invention the anode is in theform of a tubular eyelet extending transversely through an elongatedhollow member and adjacent one end thereof, and

25 means are provided for circulating a cooling medium in the hollowmember and about the tubular eyelet, whereby the anode may be maintainedat a safe operating potential and the power capacity of the magnetronincreased.

In accordance with another feature of this invention the cathode issupported by and between magnetic members secured to the ends thereof.The magnetic members or blocks may be supported in turn by resilientstrips mounted upon 35 substantially semi-cylindrical metallic supportsopposed to each other and encompassing and coaxial with the elongatedhollow member.

In accordance with still another feature of this invention, the magneticblocks are provided with recessed portions into which the ends of theoathode extend so that cooling of the ends of the oathode is reduced andsubstantially uniform electron emission from all portions of the cathodein juxtaposition to the anode is obtained.

The invention and the foregoing and other features thereof will beunderstood more clearly and fully from the following detaileddescription with reference to the accompanying drawing, in which:

Fig. 1 is an elevational view in perspective of a magnetron constructedin accordance with this invention, a portion of the enclosing vessel andthe electrode structures being broken away to show details ofconstruction more clearly;

55 Fig. 2 is an elevational view in section of the 1937, Serial No.151,093

magnetron shown in Fig. 1, illustrating in addition the poles of anexternal magnet;

Fig. 3 is a view in cross-section along line 3--3 of Fig. 2; and

Fig. 4 is an enlarged detail view mainly in section of one of themagnetic members and a portion of the cathode.

Referring now to the drawing, the electron discharge device there showncomprises an evacuated enclosing vessel l0 having an inwardly extendingportion l l at one end to which a metallic collar i2 is hermeticallysealed. An elongated, hollow metallic member I! having a reduced portionI4 is sealed to the'collar l2 and provided with an outlet port ortubulation l5. Disposed within the hollow member l3 and secured theretois an elongated inlet tubulation or pipe l5, which preferably extends toimmediately adjacent or into the reduced portion II. A tubular eyeletll, forming the anode element of the electron discharge device, extendslaterally through the reduced portion it adjacent the inner end thereof.A suitable positive potential may be applied to the anode through aleading-in conductor l8 affixed to the hollow metallic member l3.

During operation of the device a. cooling medium such, for example, aswater may be circulated in the hollow member l3 and about the eyelet l1so that the anode is maintained at a relatively low and safe temperatureand, hence, is capable of handling large currents.

Mounted within the vessel HI, as by rigid leading-in conductors l9, area pair of elongated, substantially semi-cylindrical, metallic members20, disposed on opposite sides of the hollow member l3, l4 and coaxialand forming a blocking condenser therewith. Preferably, thesemi-cylindrical members are of non-magnetic material. Each of thesemembers is provided with an aperture 21, in alignment with the anodeeyelet l1, into which suitable strongly and oppositely magnetized endmembers or blocks 22 extend, the apertures 2i preferably beingsufficiently large to prevent contact between the magnetic blocks 22 andthe semi-cylinders 2|). The metallic blocks 22 are supported byresilient metallic strips or cantilever springs 23 affixed to thesemi-cylindrical members 20 as by rivets 24 and biased so that they tendto move the blocks apart. As shown clearly in Fig. 4, each of themagnetic blocks 22 has a recess 25 in the inner end thereof and anenlarged head portion 26 against which the springs 23 bear. Preferably,the magnetic blocks 22 are so mounted that the inner ends thereof are inproximity to the ends of the anode eyelet ll.

A thermionic cathode 21, which may be for example a linear thoriatedtungsten filament, extends in the axis of the anode l7, each end of thefilament. as indicated in Fig. 4, being secured in a central bore in oneof the magnetic blocks 22. As will be apparent, the filament 21 is heldunder tension by the springs 23 so that the linearity thereof and thedesired coaxial relation of the cathode and anode are maintained. Thecathode may be energized from a suitable battery, not shown, connectedto the conductors i9.

Because of the recesses 25, end cooling of the filamentary cathode 21 isreduced as a result of which all portions of the cathode between theends of the anode I! operate at substantially the same temperature.Consequently, uniform emission from these portions is obtained. Also,inasmuch as the metallic blocks 22 extend into proximity to the anodel1, emission from the cathode is confined substantially to the regionbetween the ends of the anode.

The magnetic blocks 22 may be highly magnetized so that an intensehighly concentrated magnetic field parallel to the cathode and betweenthe cathode and the anode is achieved.

This field may be augmented, if desired, through the agency of anexternal magnet having poles 28 adjacent the vessel Ill and in alignmentwith the cathode 21. The field produced by the external magnet may bevaried in accordance with a signal to modulate the current flowingbetween the anode I1 and cathode 21.

In another form of the device, the blocks or members 22 may be normallyunmagnetized but of a material having a relatively high permeability. Inthis case the magnetic field is provided entirely by the externalmagnet.

The high frequency oscillating field produced by the magnetron will beconfined substantially between the semi-cylinders 20 and the cylindricalmember l3, l4, and an output current corresponding thereto may beobtained in a suitable conductor 29 disposed adjacent the upper end ofthe vessel [0. If desired, the magnetron may be mounted within adielectric guide or the outer conductor of a coaxial conductortransmission line, and the high frequency fields propagated along theguide or transmission line. In such case, it will be appreciated that aclose and efficient coupling between the oscillation generator, i. e.,the magnetron, and the transmission system may be obtained.

Although a specific embodiment of the invention has been shown anddescribed, it will be understood, of course, that various modificationsmay be made therein without departing from the scope and spirit of theinvention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising an enclosing vessel, ananode, an elongated cathode in cooperative relation with said anode, andmagnetic members within said vessel and adjacent the ends of saidcathode.

2. An electron discharge device comprising an enclosing vessel, atubular anode within said vessel, a linear cathode within said anode andsubstantially coaxial therewith, and a pair of magnetized membersadjacent opposite ends of said anode for producing a magnetic fieldadjacent and parallel to said cathode.

3. An electron discharge device comprising an anode, a filamentarycathode in cooperative re lation therewith, and means supporting saidcathode including magnetic members ailixed to the ends of said cathodeand resilient means mounting said magnetic members.

4. An electron discharge device comprising a linear filamentary cathode,an anode encompassing said cathode, magnetized members aflixed to theends of said cathode, and elongated resilient strips supporting saidmagnetic members and biased to tension said cathode.

5. An electron discharge device comprising an enclosing vessel, anelongated hollow member extending into said vessel, a tubular metalliceyelet constituting an electrode element extending laterally throughsaid hollow member adjacent the inner end thereof, a cathode extendingthrough said eyelet, and inlet and outlet ports for said hollow memberwhereby a cooling medium may be circulated through said member and aboutsaid eyelet.

6. An electron discharge device comprising an anode structure includingan elongated metallic cylindrical member, a cathode in cooperativerelation with said anode structure, a pair of semicylindrical metallicmembers on opposite sides of said cylindrical member and substantiallycoaxial therewith, and resilient means carried by said semi-cylindricalmembers for supporting said cathode.

7. An electron discharge device comprising an anode structure includinga cylindrical member and a tubular eyelet extending transversely throughsaid member adjacent one end thereof, a filamentary cathode extendingthrough said eyelet, a pair of opposed, metallic semi-cylindricalsupports on opposite sides of said cylindrical member and substantiallycoaxial therewith, and a pair of cantilever springs mounted on saidsupports and connected to the ends of said cathode.

8. In an electron discharge device, an incandescible cathode andsupporting means for said cathode including members affixed to the endsof said cathode and surrounding and spaced from said ends.

9. An electron discharge device comprising a tubular anode, a cathodeextending through and beyond the ends of said anode, and supportingmeans engaging said cathode, said means including members having atubular portion surrounding the ends of said cathode and extending intoproximity to the ends of said anode.

10. An electron discharge device comprising a tubular anode, a linearfilamentary cathode extending through and beyond the ends of said anode,magnetic members aflixed to the ends of said cathode and having arecessed portion surrounding and spaced from said cathode adjacent theends thereof, and resilient means supporting said magnetic members andmaintaining said cathode under tension.

11. An electron discharge device comprising an anode structure includinga tubular member and a tubular eyelet extending transversely throughsaid tubular member, a cathode extending through said eyelet, metallicsupporting members on opposite sides of said tubular member and eachhaving an aperture therein in alignment with said cathode, resilientstrips carried by said supporting members, and means extending throughsaid apertures, connecting said strips to said cathode.

12. A magnetron comprising an enclosing vessel, a cathode, an anode incooperative relation with said cathode, a pair of magnetic members atthe ends of said cathode and within said vessel, and magnetic meansexternal to said vessel ineluding pole-pieces in juxtaposition to saidmagnetic members.

13. A magnetron comprising an enclosing vessel, a hollow, cylindricalmetallic member extending into said vessel and sealed to one endthereof, a tubular eyelet extending laterally through said cylindricalmember, a pair of opposed, metallic semi-cylindrical members on oppositesides of said cylindrical member and coaxial therewith, saidseml-cylindical members having apertures in alignment with said eyelet,a cathode extending through said eyelet, magnetic members aiflxed to theends of said cathode and extending through said apertures,-andcantilever springs outside of said semi-cylindrical members and aflixedthereto, said springs supporting said magnetic members.

ARTHUR L. SAMUEL.

DISCLAIMER 2,130,510.Arthar L. Samuel, Summit, N. J.

ELECTRON DISCHARGE DEVICE.

Patent dated September 20 1938 Disclaimer filed M 1 assignee, BellTelephone Laboratories, Incorporated. sly 3 1940 by the Hereb entersthis disclaimer to the subject-matter of claims 1, 2, and 12.

[ cial Gazette Jane 25, 1.940.]

eluding pole-pieces in juxtaposition to said magnetic members.

13. A magnetron comprising an enclosing vessel, a hollow, cylindricalmetallic member extending into said vessel and sealed to one endthereof, a tubular eyelet extending laterally through said cylindricalmember, a pair of opposed, metallic semi-cylindrical members on oppositesides of said cylindrical member and coaxial therewith, saidseml-cylindical members having apertures in alignment with said eyelet,a cathode extending through said eyelet, magnetic members aiflxed to theends of said cathode and extending through said apertures,-andcantilever springs outside of said semi-cylindrical members and aflixedthereto, said springs supporting said magnetic members.

ARTHUR L. SAMUEL.

DISCLAIMER 2,130,510.Arthar L. Samuel, Summit, N. J.

ELECTRON DISCHARGE DEVICE.

Patent dated September 20 1938 Disclaimer filed M 1 assignee, BellTelephone Laboratories, Incorporated. sly 3 1940 by the Hereb entersthis disclaimer to the subject-matter of claims 1, 2, and 12.

[ cial Gazette Jane 25, 1.940.]

